SWINE INFLUENZA IN SUB
SAHARAN AFRICA –
CURRENT KNOWLEDGE AND
EMERGING INSIGHTS
Meseko A. Clement
DVM, MSc (Virology)
National Veterinary Research Institute, Vom Nigeria
Presented at OFFLU SIV group technical meeting in Rome, 16th -17th April
2013
Background
• Swine influenza virus (SIV) is an ‘emerging
disease’ in Africa unlike African Swine Fever
(ASF)
• Though pigs are widely kept in the region, they often
receive less attention in contrast with poultry and
ruminants
• Pigs contribute substantially to livestock
development, trade and livelihood in the region
• Diseases like SIV- classical or pandemic can
jeopardize swine health/production and endanger
public health.
Pig husbandry in Africa
• Global pig population is estimated at around
923 million
• 552 million (60%) are found in Asia, 194
million in Europe, 81 million in South and
Central America, 72 million in North America
• About 18 million (2%) pigs are ascribed to
Africa?
• Nigeria with over 6 million swine accounts for
over 30% total pig production in Africa
(FAOSTAT,
2002)
Pig husbandry in Africa
• Gambia and Senegal for instance have just
about 25,000 and 325,747 heads of pigs
respectively (FAO, 2009)
• In Ghana, 1998 estimate puts the pig
population at about 400,000 (FAO, 1998)
• Lower concentration of pigs in some countries
in the sub region is attributable to social and
religious bias (Permin et al., 1999)
Pig husbandry in Africa
• Pigs are reared virtually in all countries in
Africa including Egypt where over 300,000
pigs were slaughtered at the beginning of the
2009 swine flu pandemic
• Two major husbandry practices in Africa are:
free range/backyard farming in rural areas
intensive, commercial piggery in peri-urban
and urban centres
(Kerr, 2010)
Free range pig in Northern Nigeria
Hog hole Gashaka forest
Backyard piggery in Taraba
Human
Avian
Movement
Swine
Pig husbandry in Africa
• The intensification of pig farming operations in urban and
peri-urban areas favours circulation of pathogens at the
human-animal interface (Vibound et al., 2006)
• This is often aggravated by poor sanitation, waste
management and disease control practices
• According to a study by ILRI, the Institute of Zoology (UK)
and the Hanoi School of Public Health in Vietnam - Ethiopia,
Tanzania, Nigeria all in sub Saharan Africa and India are the
top 4 geographical hotspots of zoonotic diseases
• Infections like swine influenza virus pose both economic and
public health risks (Shrestha et al., 2002; Verhulst 1993).
Africa and swine influenza
• Data on swine influenza virus in sub Saharan
Africa is scanty
• This may not be due to the absence of virus
activity in wide scale free range or commercial
pig production in the region
• But poor surveillance and the absence of
coordinated reporting and documentation
systems (Schelling, 2005)
Africa and swine influenza
• African Swine Fever (ASF) is by far the most
important cause of morbidity and mortality in
pigs in the region (El Hicheri et al., 1996; Nana-Nukechap and Gibbs, 1985)
• Few studies on SIV are limited to serology in
either pig or human from Nigeria, Ghana,
Mali, Zambia, Egypt and South Africa
(Shalaby,1981 ;
Olaleye et al., 1990; Stafford et al., 1992; )
Africa and swine influenza
• Could it be that SIV was not known to Africa
as was reported for Australia prior to 2009
pandemic?
•
(influenza virus infection has not been previously confirmed in Australian pigs
until pandemic H1N1 was first identified in 2009 (Holyoake et al., 2011)
• As at April 2013, there are only two deposits
of SIV sequences in the Genebank from Africa
-Cameroun (free range) and Nigeria (intensive farm)
• Retrospective and prospective examination of
data in Africa is important to define SIV
subtypes in the region
GAPS IN KNOWLEDGE
• SIV surveillance and research in Africa is
hitherto neglected compared to other
infectious diseases like ASF
• No known SIV lineage has been described in
literature with respect to Africa!
• According to ILRI report- generally, zoonoses
and animal diseases in underdeveloped
countries are "massively" underreported and
99.9% of all livestock losses in sub-Saharan
Africa are never registered in official disease
reports
GAPS IN KNOWLEDGE
• SIV is not a listed (reportable) disease by OIE
• Could that have affected the status of
investigation and reporting of swine influenza
in pigs regardless of production and
productivity losses?
• A recent study in West Africa suggested
influenza may not be a problem among pigs
because samples tested in three countries all
returned negative (Couacy-Hymann et al., 2012)
Challenges ahead
• In view of serological evidence of
classical swine influenza reported in
times past ((Shalaby,1981 ; Olaleye et al., 1990; Stafford et al.,
1992; )
• Surveillance to detect classical SIV need
to be intensified in order to better
describe African lineage of SIV for
research and diagnosis
Challenges ahead
• Though isolation of the virus in Cameroon was a one
time report in free range pigs
• There were several confirmed cases in Nigeria over
two years (2010-2012)
• As at February 2013, pandemic H1N1 was still
positively identified in pigs in the same
epidemiological zone in Nigeria
• 89 (29.4) of 302 sera analyzed by ELISA was also
positive for influenza A
• HI test showed 97.7% (pdm H1/H1), 2.3% (H3)
Phylogenetic
tree of the HA
gene of 2009
pandemic
A/H1N1
influenza virus
HA-gene
17
Challenges ahead
• SIV (pdm) may become endemic in Nigeria like it was when
Spanish flu (1918) was introduced and entrenched in pigs
globally
• The virus may spread around the country and across borders
• Mutations have been observed-Q240R(H1-numbering) in the antigenic site
of the HA gene compared to related virus
• S31N mutation on the M2 protein conferring resistance to adamantane
antivirals like other pandemic SIV
• Reassortments among classical, seasonal and pandemic strains
of SIV is another possibility! (CDC, 2012 )
• Human contacts may get infected or re-infected !
• Novel and pandemic strain may emerge !(lessons from H7N9
in China)
Recommendations
• Surveillance, monitoring and research on circulating
swine influenza in Africa is important as currently in
place for ASF to define circulating lineage in this
region for diagnostics, research and vaccine
production purposes focusing on:
 commercial piggery
 Human-animal interface
 Free roaming/backyard pigs
 Live pig markets
• Accumulation and sharing of virological and
epidemiological data from the region
• Implementing control measures including
enlightenment and biosecurity
Affiliation & Collaborators
• FAO Regional Lab for Animal Influenza, National
Veterinary Research Institute, Vom Nigeria
• Virology Department, College of Medicine,
University College Hospital, University of Ibadan,
Ibadan Nigeria
• FAO/OIE Reference Center for Animal Influenza and
Newcastle Disease virus, IZSVe, Padova Italy
Acknowledgement
Robert S. McNamara World Bank Fellowship
20
References
•
Appiah P., E. K. Tham-Agyekum, R. Yeboah, and F. Nimoh, 2011: Awareness and Knowledge Level of Swine Flu among Pig Farmers in the Ashanti
Region of Ghana. Int. J. Pure Appl. Sci. Technol., 2(1) :47-53.
•
Bao Y., P. Bolotov, D. Dernovoy, B. Kiryutin, L. Zaslavsky, T. Tatusova, J. Ostell, and D. Lipman, 2008: The
National Center for Biotechnology Information. J. Virol. 82(2):596-601.
•
Viboud C, WJ Alonso, L. Simonsen, 2006: Influenza in tropical regions. PLoS Med 3:e89 Verhulst, A., 1993: Lessons from field experiences in the development of
monogastric animal production. In: Mack, S. (Ed.), Strategies for Sustainable Animal Agriculture in Developing Countries. Proceedings of the FAO Expert. Rome
Italy
•
Shrestha, N.P., S.A Edward,., J.F Robertson,., 2002: Factors affecting reproductive performance in the Nepalese Pakhri-bas pig: effect of nutrition and housing during
gilt rearing. Asian-Australian Journal of Animal Sciences 15 (1) 72-78.
•
Shalaby M.A., B.M Nati., M.S Saber. and A.H. Hosny 1981: Serological studies on swine influenza in Egypt. Int J. Zoon. 8: 100-106.
•
Stafford K., Y. Stafford., D. Paton., P. Gamble., 1992: Antibodies to some swine diseases in commercial piggeries in central Zambia. Rev. Elev Med Vet
pays Trop 45(3-4): 229-30
•
Permin A., L. Yelifari., P. Bloch., N. Steenhard., N.P Hansen, P. Nansen, 1999: Parasites in cross bred pigs in the upper East Region of Ghana- Veterinary
Parasitology 87 (1) 63-71
•
Olaleye, OD, S.A. Omilabu, S.S. Baba, A.H. Fagbami, 1990: Haemagglutination-Inhibiting (HI) Antibodies against strains of Influenza A virus in Horse and pig sera
in Nigeria. J. Hyg, Epidemiol. Microbiol. and Immunol, 34, 4: 365-370.
•
Njabo K. Y., T. L. Fuller , A. Chasar , J. P. Pollinger , G. Cattoli, C. Terregino , I. Monne , J. Reynes , R. Njouom , T. B. Smith, 2012: Pandemic A/H1N1/2009
influenza virus in Swine, Cameroon, 2010. Veterinary Microbiology 156 (1-2) : 189–192
•
Nana-Nukechap M.F., E.P. Gibbs,1985: Socioeconomic effects of African swine fever in Cameroon. Trop Anim Health Prod. 1985; 17:183–4.
•
Kerr, W.A. (2010). International Law and Trade policy: Political precaution, pandemics and protectionism, Vol 10 No 2. http://International .Vlex.com/vid/precautionpandemics-protectionism-68232724.
•
International Livestock Research Institute (2012). ILRI-DFID report: Mapping of poverty and likely Zoonoses hotspots in the world. http:www.medical
newstoday.com/articles. Accessed 08 July 2012.
•
FAO, 2009: FAOSTAT-Agriculture, FAO, Food and Agriculture Organisation of the United Nations. Rome, Italy. http://faostat.fao.org.
•
El Hicheri K, C. Gomez-Tejedor, M.L. Penrith, G. Davies, A. Douati, G.J. Edoukov, 1998: The 1996 epizootic of African swine fever in the Ivory Coast.
Rev Sci Tech. 17:660–73.
•
Holyoake et al., (2011). First identified case of pan H1N1 influenza in pigs in Australia. Australian Vet J. 2011: 89427-431
•
Couacy-Hymann et al., (2012). Surveillance for influenza viruses in poultry and swine in West Africa -2006-2008. EID
Influenza Virus Resource at the
Thank you